The invention concerns a process for the sequence control of sequential object-oriented system simulations in which objects with at least several identical properties are combined to form object groups and the object groups are mapped into classes and each class is realized by a simulation program part, whereby the mapping of an object from an object group in an instance of a class occurs in such manner that the instance is realized by setting at least one parameter in the simulation program part, whereby the latter becomes a parameterized simulation program part, in which the instances for simulation of communication between objects generate and process events, which is realized by a sequence of the parameterized simulation program parts, whereby the simulation sequence is controlled by activations of instances.
A system simulation is the execution of a computer-controlled program, which models the system to be tested in an abstraction sufficient for the investigation purpose. A dynamic simulation represents a system in the same way as it responds in time. A time-discrete simulation is a dynamic simulation in which the states of the objects participating in the simulation change at discrete time points in a continuous time scale. Such simulations are realized, for controlling the size and complexity of such programs, in line with an object-oriented principle, i.e. the program consists of program objects which communicate with each other.
Time-discrete system simulations are typically used in the telecommunications industry for designing, optimizing and validating radio-communication access networks as, in contrast to static “Monte Carlo simulations”, they can simulate a time history of the simulated model, which is necessary for analyzing the influence resulting from the movement of mobile radio-communication participants, a large number of packet-switched services or also the increasing use of adaptive components in radio-communication access networks, for example with a WCDMA multiple access process. As a result, time-discrete system simulations are also particularly suitable in order to be able to examine algorithms of a radio-communication access network, such as those which occur during administration of the radio-communication network. in this context a radio-communication access network is the radio-communication network-relevant part of a mobile radio communications network.
Control of the sequence between objects in time-discrete simulations is a task of the simulation sequence control, which implements one or more simulation processes. A simulation process is, for example, the semantics of communication between objects, according to E. A. Lee and A. Sangiovanni-Vincentelli: A Framework for Comparing Models of Computation, in IEEE Transactions on Computer Aided Design of Integrated Circuits and Systems, vol. 17(12), pp. 1217-1229, Dec. 1998.
In E. A. Lee, “Modeling Concurrent Real-time Processes Using Discrete Events”, invited paper, Annals of Software Engineering, Special Volume on Real-time Software Engineering, vol. 7 (1999), pp. 25-45. Feb. 1997, a sequence control of a time-discrete simulation is represented by means of discrete events. The communication between objects is handled via events here. In addition to the information to be exchanged between objects, the information value, events include an address value which can consist of the source address and target address, and a time stamp, via which they can be arranged in a chronological order, for example. Further possible arrangement criteria are a topological sorting or user-dependent priorities of the communicating objects.
As a result of the event searching with the smallest time stamp respectively in the central event memory and the forwarding of this event to the object receiving the event as well as its processing of the event and the return of no, one or several events to the central event memory, the simulation and hence the simulation time progresses, as can be seen in FIG. 1. Simulations by means of discrete events therefore belong to a group of run-time-planned simulation processes. Run-time-planned simulation processes only plan or generate the sequence of the simulation as far as the run-time of the program itself. In contrast to this, compiler-time planned simulation processes plan the sequence of a simulation before execution of the program.
In extensive simulations, very many events occur through communication between the objects. These events must be classified in the list or lists of the central event memory, even if they serve for communication between completely independent objects. Both the assignment to these lists and the event search with the smallest respective time stamp can be very time consuming when there are very long event lists with very many events.
The latest knowledge concerning the theory of time-discrete system simulations shows, amongst other things, in (J. Voigt and G. Fettweis: A Cycle-Based Approach for Parallel Simulations of Mobile Communications Networks, in: Symposium on Performance Evaluation of Computer and Telecommunications Networks (SPECTS'2k), pp. 139-143, Vancouver, BC, Canada, Jul. 2000) and in DE 101 04 926 A1, that the communications of objects can occur synchronously and also in an event cycle. The sequence of the simulation is already known before the beginning of a simulation through knowledge concerning the synchronism of the reception time of the events and hence the event cycle.
Sequential simulations by means of a discrete event must inevitably handle all events in one global defining relation. This can oppose the nature of the system to be simulated or lead to an over-specification of the model, which can be regarded as detrimental as it requires a great deal of computing time. A further disadvantage lies in the fact that they require a central event memory which brings all of the events occurring in the simulation into the requisite global definition relation.
In addition to the detrimental requirement of high resource utilization associated with this, a relatively large amount of the total computing time for a simulation must therefore be used for sorting the lists of the central event memory alone.